No Good News for Waiting Chelsea Investors

Chelsea Therapeutics (NAS: CHTP) investors have an anxious wait as they anticipate data from the clinical trial the FDA is requiring before approving its neurogenic orthostatic hypotension treatment Northera. Some good news in the interim would be a warm welcome.

CH-4051 was being tested in patients that failed to adequately respond to methotrexate, a generic that's typically the first line of treatment for rheumatoid arthritis. The control arm got methotrexate again, but the drug was able to elicit at least a 20% improvement in symptoms, called an ACR20, in 56% of the patients.

In theory, the response shouldn't be that high, but the result isn't that surprising. Rheumatoid arthritis trials are notorious for having high placebo effect because the symptoms are reported by the patients. Taking something, anything, can make patients feel better. Lexicon Pharmaceuticals (NAS: LXRX) , for instance, saw a 49% response for patients taking placebo in its trial testing LX2931. For Chelsea's trial, the patients were getting methotrexate, but it was probably their minds that were doing much of the healing.

Chelsea said the response in the methotrexate-treated group "confounded" the analysis, which I would agree with, but the drug still doesn't look like it's working. The best ACR20 score was only 45.8%, and there doesn't seem to be any type of dose response. The 3-mg dose produced a lower ACR20 than the 0.3-mg and the 1-mg doses.

Chelsea is making the right decision abandoning CH-4051 to focus on Northera. The data just doesn't look that good and the oral rheumatoid arthritis market looks like it's going to get really crowded with Pfizer's (NYS: PFE) tofacitinib on the verge of approval and Rigel Pharmaceuticals (NAS: RIGL) and Incyte (NAS: INCY) not that much further behind.